The invention discloses a MEMS film bulk acoustic resonator. The MEMS film bulk acoustic resonator comprises two resonant units symmetrically arranged; each resonant unit comprises a resonant structure, a supporting structure and a coupling structure; wherein the resonant structure is annular or block-shaped, the supporting structure is used for supporting the resonant structure, and the couplingstructure is connected with the resonant structure. When the MEMS film bulk acoustic resonator operates, a coupled electrostatic voltage is applied to the coupling structure, and a weak coupling is formed between the two coupling structures of the two resonant units. Through designing the weak coupling structure of the two resonant units on the basis of a conventional MEMS film bulk acoustic resonator, the MEMS film bulk acoustic resonator can realize high-sensitivity detection and suppress common mode interference.